This project will contribute to our knowledge of gibbons (the lesser apes) in several ways. First, new DNA sequences will be generated for all of the gibbon species. These new sequences will be used to construct an evolutionary tree for the gibbons, and this tree forms a base from which to study other evolutionary questions. A tree of the four subgenera and nine species of gibbons will be constructed using three independent DNA sequence data sets: one from the mitochondrial cytochrome oxidase subunit II gene, one from the glucose-6-phosphate-dehydrogenase gene encoded on the X chromosome, and one from the zinc finger gene encoded on the Y chromosome. Levels of DNA sequence divergence will also be used to assess taxonomic status of species and subspecies relative to other well-accepted primate pairs. These data also will be used to estimate the date of the split of gibbons from the great apes, and the subsequent gibbon radiation. Morphological, vocal, and behavioral characters will be mapped onto the tree to study aspects of character evolution. Finally, species-specific diagnostic sites will be identified, which may assist in conservation efforts since several gibbon species are classified as endangered.
